Frangible opening device for containers



March 7, 1967 B. EDWARDS FRANGIBLE OPENING DEVICE FOR CONTAINERS Filed June 28, 1965 Fig. 2

I N VE NTOR. Bryant Edwards JWZ;

United States Patent Office 33 01746 Patented Mar. 7, 1967 3,307,746 FRANGIBILE OPENING DEVICE FUR CGNTAINERS Bryant Edwards, Clarendon Hills, flit, assignor to Iilinois Tool Works Inc., Chicago, Ill., a corporation of Delaware Filed June 28, 1965, Ser. No. 467,620 1 Claim. (Cl. 222-143) The present invention relates to a new and improved container opening device, and more particularly, to a container opening device of the frangible or rupturable variety for use with a thin wall thermoplastic container element to afford access to the container contents.

Many new manually operable container opening devices are presently being used on a wide variety of metallic, paperboard and thermoplastic containers. In most cases, each container comes equipped with a tear tab, strip or the like which, when operated in the desired manner, exposed a dispensing aperture or makes it possible to remove a designated portion of the container such as the container top for access to the contents thereof. In constructing containers to accommodate manually operable container opening devices, it has, in the past, become necessary to provide or afford weakened connecting areas between the container opening device and a des ignated portion of the container, but this also increases the unit cost per container and creates manufacturing and assembly problems. Difficulties of this sort are primarily inherent in metallic and paperboard containers, particularly where it is desired to provide a removable, yet leakproof manually operable container opening device.

With the advent of thermoplastic materials, it has become possible to provide a frangible or rupturable, yet leakproof opening means in a container. As an example, it is now well known that a container element, which may either be'a closure or a receptacle portion, may initially be formed with a projection or protuberance which, upon pressure being applied thereto, will cause tearing of discrete areas in the vicinity of the projection or protuberance to expose one or more dispensing apertures. There have been several approaches which incorporate this basic principle and although each serves well for the primary purpose intended-facilitating the opening of disposable containers-accidental or inadvertent opening is not uncommon, and container stacking has not been entirely satisfactory. To overcome this, the projection or protuberance has been placed in a recess formed in the container, but this has only partially alleviated accidental opening and stacking difficulties. In addition, prior art opening devices for thermoplastic containers and the like have required a substantial amount of force to successfully operate the same without any assurance of uniform pressure being applied to selective areas capable of fracture, and it has not been possible to effectuate reclosure. There has thus been a long felt need fora container opening device in disposable containers which retains all the advantages of the prior art approaches without any of the above noted or other deficiencies.

Accordingly, it is an object of the present invention to provide a new and improved manually operable container opening device for disposable or throw-away containers.

Another object of the present invention is to provide a container opening device of the aforenoted type which prevents accidental opening of the container and permits stacking of containers one above the other.

Still another object of the present invention is the provision of a container opening device of the foregoing type which is leakproof prior to operation, readily removable from the container when it is desired to gain access to the container contents, and is reclosable.

A further object of the present invention is the provision of a container opening device which provides one or more dispensing apertures primarily, although not exclusively, for the insertion of a drinking straw or for pouring of the container contents therethrough.

Yet another object of the present invention is the provision of a container opening device of the type discussed which can be formed during the container manufacture by well known thermo-forming techniques without great difficulty or expense.

These and other objects and advantages of the present invention are obtained by the provision of a thermoplastic container element having a depression or cavity therein, and in which depression or cavity there is provided a protuberance or knob member of a size enabling manual grasping thereof such that upon pulling the protuberance or knob member, discrete material areas in the vicinity of the depression or cavity are ruptured or torn to afiord' access to the container contents.

In the drawing:

FIG. 1 is a fragmentary perspective view of a thermoplastic container element incorporating my novel manually operable container opening device;

FIG. 2 is a fragmentary sectional view showing a pair of container members or elements in stacked relationship;

FIG. 3 is a top plan view of the container and its opening device as seen in FIG. 1, but slightly reduced in size in relation thereto;

FIG. 4 is a fragmentary perspective View of the container and its opening device as seen in FIG. 1 of the drawing after the same has been operated to expose dispensing apertures;

FIG. 5 is a fragmentary sectional view of the container and its opening device as seen in FIG. 1 of the drawing;

FIG. 6 is a fragmentary sectional view of the container and its opening device as seen in FIG. 4 of the drawing; and

FIG. 7 is a modified form of my novel container opening device which comes within the purview of the present invention.

Referring now to the drawing, there will be seen in FIG. 1 a thermoplastic container element or member 10, polystyrene being one preferred example, which may either be a closure or receptacle portion. The container element 10 shown in FIG. 1 of the drawing is of the closed top receptacle variety having a top wall or end surface 12, and a circumferentially continuous side wall 14, here shown to be cylindrical in form, which depends from the top wall or end surface 12 and extends downwardly toward an open bottom portion (not shown). Closed top receptacle portions are filled through the open bottom, and when this has been accomplished, a bottom closure element is applied to the receptacle portion to hold the container contents therewithin. The dotted or phantom lines shown in FIG. 1 are intended to depict the bottom of a lid or closure rim to make it apparent that the manually operable container opening device, now to be discussed, can be used either with a closure or receptacle portion.

In its preferred form, the manually operable container opening device generally designated 20 in FIG. 1 of the drawing comprises an inverted frusto-pyramidal shaped aaomae Wall structure 22 formed in the end surface 12, and a hollow knob member in the form of an oppositely directed protuberance or projection 24. The frusto-pyramidal shaped wall structure 22 includes four downwardly and inwardly inclined side walls 26 which are integrally joined at their lower ends to the bottom wall portion 28.

Adjacent side walls 26 are disposed at an angle of approximately 90 degrees to each other to form corner po-rtions 30 extending therebetween. In a frusto-pyramidal shaped wall structure 22, there will be four such corner portions which will expose a like number of dispensing apertures as will now be discussed.

When it is desired to gain access to the container contents, the knob member 24 should be gripped and pulled toward and through the plane of the end surface 12. As the knob member 24 is moved towards and eventually beyond the end surface 12, the material adjacent the corner portions 36' where they meet the end surface 12 such as at 32 will first be ruptured since concentrated loads, initially and substantially simultaneously applied to the corner portions 30, will first be directed or transmitted to the material portions 32. In other words, loads derived from the outward pulling of knob member 24 will be transmitted along the corners St to the areas or portions 32 which will be the first to yield or rupture due to the concentration of load at these points. The concentrated loads are sufficient to cause rupture of the material portions 32 at the upper end of the corner portions 39, after which movement of the knob member through the plane of the end surface 12 causes rupture of the material adjacent the corner portions 39 to form the dispensing apertures 34. As seen in FIG. 4, the openings 34 which are formed are diamond-shaped, and are each surrounded by portions of the side walls and end surface. It is also to be noted that the central location of knob member 24 in this embodiment enables uniform pressure to be applied through each of the corner portions 34 when the knob member is pulled upwardly.

When the knob member 2A is fully extended as is depicted in FIG. 4 of the drawing, the side walls 22 act as struts preventing the return of the bottom Wall portion 28 so that the dispensing apertures 34 will be maintained in an open position until the knob member is returned to the position shown in FIG. 1. If it is desired to subsequently reclose the container, it is a relatively simple matter to merely depress the knob member 24 to the position shown in FIG. 1, the effect of which will close the opening between adjacent side wall portions 22 as will be apparent.

As best seen in FIG. 5 of the drawing, the knob member 24 has its upper or top wall slightly below the plane of the end surface 12 to permit stacking of adjacent container elements above each other as seen in FIG. 2 without interference from the knob member. If desired, the upper or top wall of the knob member 24 may lie wholly within the confines of the plane containing the end wall 12, but it should not project above the end surface 12 unless the bottom wall portion of an adjacent container is of the indented or false bottom variety. FIG. 6 of the drawing shows the degree to which the knob member 24 may be projected above the plane of the end surface 12, and the relative height of the dispensing apertures 34 in relation thereto. It will be understood that the size of the dispensing apertures 34 is directly dependent upon the spacing between the side walls 22 and the depth of the bottom wall portion 28 in relation to the end surface 12.

Although the surrounding wall structure 22 is designed to provide a plurality of dispensing apertures 34, it will be apparent that the principles of the present invention apply to wall structures of any shape or configurations having one or more corner portions 36 or similar structure. As an example, a modified form of the invention is shown in FIG. 7 of the drawing,

and is generally similar to the form of the invention shown in FIGS. 16 as indicated by the application of identical reference numerals with the suffix a employed to designate like parts. In this particular embodiment, the thermoplastic container element 10a has a manually operable container opening device 20a similar to the one just discussed with the exception that the surrounding wall structure 22a is formed to provide only a single corner portion 30a. When the knob is operated, the material portions 32a, where the upper end of the corner 38a joins the end surface 12a, and then the material portions adjacent the corner 30a will separate in the same manner as the first embodiment discussed.

The knob member 24 in the FIGS. 1-6 embodiment and the knob member 24a in the FIG. 7 embodiment may be of any desired shape, but must be sufliciently enlarged to enable manual grasping thereof. The knob members are preferably initially formed as an integral part of the container element to facilitate manufacture and reduce cost, but it will be understood that they may be subsequently attached to the bottom wall portions of the surrounding wall structure in any suitable manner. In the embodiments shown in the drawing, the knob member has an outer knurled surface to facilitate grasping thereof, but any other means, including the shape or configuration of the knob member, may be used to enhance the gripping thereof by a user.

From the foregoing, it will not be appreciated that the present invention contemplates a new and improved manually operable container opening device for containers of the disposable or throw-away variety. The manually operable container opening device can be applied to any part of a container body or element, but preferably is situated in the end surface of a closure or receptacle portion. Prior to being operated, the container opening means is positioned below the plane of the surface from which it extends to permit stacking of adjacent container elements while at the same time preventing inadvertent actuation thereof such as might occur during container stacking or handling. The construction of the container opening means facilitates quick and easy operation thereof to expose one or more dispensing. apertures, and also enables subsequent reclosure of the container if desired.

Although specific embodiments of the invent-ion have been shown and described, it is with full awareness that many modifications thereof are possible. The invention is thus not to be restricted except in so far as is necessitated by the prior art and by the spirit of the appended claim.

I claim:

A one-piece seamless thermoplastic container member having an inverted frusto-pyramidal shaped wall structure formed in a planar end wall surface and including a bottom and side walls extending upwardly and outwardly therefrom and terminating in an open upper end in the vicinity of the plane of said end surface, and a hollow, closed top knob member joined to said bottom wall at a location generally equally spaced from the side walls of the frusto-pyramidal shaped wall structure and extending upwardly toward said end wall surface, said knob member having a height less than the depth or" the side walls to permit stacking of similarly configured container members without accidental operation of said knob member, said knob member including means facilitating grasping thereof and being of a size to enable manual grasping such that when moved toward said planar end wall surface, the surrounding wall structure is severed in the vicinity of the juncture of said side walls to expose a plurality of elongated openings for dispensing purposes, the arrangement of the aforementioned elements also causing severing of the planar end wall surface in the vicinity of the juncture of the side walls therewith to provide relatively large elongated 5 6 dispensing openings facilitating egress of the container 2,898,018 8/1959 Borah 222-529 contents. 3,003,668 10/1961 Sherlock et a1 222-541 3,042,271 7/ 196 2 Winstead 222-529 Re n s i e y he Examiner 3,076,584 2/1963 Sherlock 222-541 UNITED STATES PATENTS 5 3,204,827 9/1965 Krautkramer 222-143 2,914,734 10/1952 SlYk 222-565 RAPHAEL M. LUPO, Primary Examiner.

2,893,611 7/1959 Akers 222-541 X 

